Income Taxes (Schedule Of Temporary Differences That Give Rise To Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Income Taxes [Abstract]
Accrued expenses	$ 10,666	$ 12,243
Compensation and retirement plans	52,986	33,298
Tax credit and NOL carryforwards	723	1,173
Inventory reserves	7,482	9,545
Other	3,262	3,311
Deferred tax assets:	75,119	59,570
Valuation allowance	(522)	(692)
Net deferred tax assets	74,597	58,878
Depreciation and amortization	(38,796)	(37,112)
Other	(394)	(1,119)
Deferred tax liabilities	(39,190)	(38,231)
Net deferred tax asset	$ 35,407	$ 20,647